For the purpose of this application, unless otherwise indicated expressly or impliedly by the context of the description, the term “conduit” shall mean an opening in a camera shutter module designed to allow the passage of light therethrough. Likewise, the term “aperture” shall mean an apparatus for allowing less than 100% of an amount of light through a conduit.
Also, the terms “camera shutter module” and “miniature camera shutter module” shall mean an apparatus incorporated within a camera optics system used to affect the amount and/or quality of light passing through the optics system to an imaging surface whether or not the apparatus is configured for shuttering light. For example, a miniature camera shutter module may refer to an apparatus configured for shuttering light, or for an apparatus configured for affecting the amount and/or quality of light without actually shuttering light. Of course, a miniature camera shutter module may also refer to an apparatus configured for shuttering, filtering and for providing an aperture for light in a camera optics system.
Cameras commonly include mechanical structures for shuttering light, adjusting an amount of light and adjusting the quality of light that is able to pass through a conduit and fall incident upon an imaging surface.
The camera shutter is a device that alternatively allows light to pass through a conduit to an imaging surface for a certain period of time and blocks the light so as to limit the time light falls incident upon the imaging surface. It is advantageous to have the ability to control the shutter speed, or the time the imaging surface is exposed to light. Furthermore, in digital camera applications, it is important to shutter light in order to allow an imaging surface to process an exposure of light.
It is also advantageous to control the percentage of an amount of light that is exposed to an imaging surface. An aperture is a device which can be used to limit the total amount of light able to pass through a conduit onto an imaging surface. For example, a smaller aperture lets less light onto the imaging surface so that bright images may be processed, whereas a larger aperture allows more light onto the imaging surface to expose darker images. It is also advantageous to control the quality of light falling incident upon an imaging surface by utilizing filters. For example, it may be desirable to reduce the intensity of the light passing through to an imaging surface. Neutral density filters reduce light of all relevant wavelengths from entering an imaging surface. Using a neutral density filter allows a user to reduce a portion of light while maintaining a constant aperture setting. Neutral density filters are particularly useful in preventing overexposure during bright conditions. Also, in some instances it is desirable to filter particular wavelengths of light. For example, ultraviolet filters are used to reduce haziness in images created by ultraviolet light. In other camera applications, color filters are used to compensate for the effects of lighting or for contrast enhancement.
Notwithstanding the advantages provided by utilizing shutters, apertures and filters in photography applications, their use has not been adequately utilized in miniature camera applications such as cameras incorporated into cellular phones, personal digital assistant devices, and the like. This is because, it is oftentimes the case that the camera lens chassis of such devices are designed such that it is impossible or extremely impracticable to include shutters, apertures and filter modules. For example, digital camera applications typically require the use of sensitive position sensors to track the position of certain components in the optical train and to adjust the system setting as those components move in relation to an image sensor, such as an array of charge-coupled devices (CCD) or a CMOS sensors. In such applications, it is important not to crowd the sensor or else the image will not be processed correctly. Known techniques do not adequately address this problem.
Furthermore, it is often the case that a shutter should be placed as close to the plane of a conduit as possible for calibration and image processing purposes. As such, the problems associated with sensor crowding are not able to be obviated simply by placing a shutter at a more convenient place along an optical train, but at a distance from the conduit.
As explained above, it is difficult to house a module for controlling shutters, apertures and filters, among other components, within a miniature camera chassis. However, the use of these components if oftentimes crucial in camera applications. For example, shutters are required to block light as a imaging sensor processes an exposure. Also, apertures and filters are oftentimes needed to reduce and filter light so that an image does not become overexposed or washed out.